Wadena County climate

Wadena County Frost Dates and Growing Season

NOAA 1991-2020 normals for Wadena 3 S, 25.4 km from Wadena County, elevation 1372 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Wadena 3 S. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around May 10 and the first fall freeze around September 30, a growing season of about 141 days.

Median at 36°F
last May 20, first September 21
Median at 32°F
last May 10, first September 30
Median at 28°F
last April 30, first October 10

Last freeze in spring

The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.

Threshold10%20%30%40%50%60%70%80%90%
36°FJun 2May 30May 27May 24May 20May 18May 15May 11May 7
32°FMay 25May 19May 15May 13May 10May 7May 4May 2Apr 29
28°FMay 13May 8May 5May 2Apr 30Apr 29Apr 26Apr 22Apr 18
24°FMay 2Apr 29Apr 26Apr 23Apr 20Apr 17Apr 14Apr 10Apr 6
20°FApr 22Apr 18Apr 15Apr 12Apr 10Apr 7Apr 5Apr 2Mar 28
16°FApr 16Apr 11Apr 9Apr 5Apr 3Apr 1Mar 30Mar 25Mar 19

First freeze in fall

The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.

Threshold10%20%30%40%50%60%70%80%90%
36°FSep 9Sep 13Sep 17Sep 19Sep 21Sep 24Sep 27Sep 30Oct 3
32°FSep 17Sep 21Sep 24Sep 27Sep 30Oct 2Oct 5Oct 9Oct 13
28°FSep 25Sep 30Oct 3Oct 6Oct 10Oct 13Oct 16Oct 20Oct 25
24°FOct 6Oct 11Oct 16Oct 19Oct 23Oct 26Oct 29Nov 1Nov 5
20°FOct 16Oct 23Oct 27Oct 30Nov 1Nov 3Nov 6Nov 9Nov 14
16°FOct 28Nov 1Nov 3Nov 6Nov 9Nov 11Nov 14Nov 17Nov 21

Growing season length

Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.

Threshold10%20%30%40%50%60%70%80%90%
36°F141135131127123119115109104
32°F160154149145141138134128122
28°F182175170165161157153148141
24°F204196192187183179175170161
20°F220215210206203198194189181
16°F237229224221217214210206197

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder
100% of years
32°F or colder
100% of years
28°F or colder
100% of years
24°F or colder
100% of years
20°F or colder
100% of years
16°F or colder
100% of years

Degree days

A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.

Heating degree days, base 65°F
9,298
Cooling degree days, base 65°F
318
Growing degree days, base 40°F
3,691
Growing degree days, base 45°F
2,769
Growing degree days, base 50°F
1,962
Growing degree days, base 55°F
1,275
Growing degree days, base 60°F
718

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,76200
February1,47300
March1,22603
April735028
May36014178
June10667413
July40126552
August6484485
September25026251
October658150
November1,08902
December1,53600

What this means

NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.

The station is 25.4 km from Wadena County. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

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Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00218579 (Wadena 3 S). Public domain.